OTTAWA — The Rev. Gretta Vosper is a dynamic, activist minister with a loyal following at her Protestant congregation in suburban Toronto. She is also an outspoken atheist. “We don’t talk about God,” Vosper said in an interview, describing services at her West Hill United Church, adding that it’s time the church gave up on “the idolatry of a theistic god.” Vosper’s decision to reject God, Jesus Christ and the Holy Spirit and to turn her church into a haven for nonbelievers “looking for a community that will help them create meaningful lives without God” has become too much even for the liberal-minded United Church of Canada. The United Church, the country’s largest Protestant denomination, has begun an extraordinary process that could end up stripping Vosper of her rights to continue as a minister. Last week, a special committee of the Toronto Conference of the United Church requested that a formal hearing be convened by the General Council of the United Church to determine her fate as a minister.